At present, more and more electronic devices are provided with touch display panels, such as an information inquiring machine in a hall of a public place, a computer and a cell phone which are used in daily life and work for users and the like. Electronic devices can be operated by touching identifications on touch display panels by fingers of users, being free from keyboards and mice, so that man-machine interaction is more direct. In order to meet requirements of users better, generally, a touch display panel is internally provided with a pressure sensor for detecting the amount of touch pressure in the process of touching touch display panels by users.
In the related art, a piezoresistive pressure sensor used in a touch display panel is mainly formed by connecting strain electrical gauges according to a Wheatstone bridge principle. The kind of sensors is low in piezoresistive coefficient, so that enough strong signals can be detected only when the sizes of the sensors are enough large, but the larger the size of the pressure sensor is, the more difficult it is to integrate the pressure sensor into a touch display panel.